Barking is normal dog behaviour. Excessive barking is a symptom, and the treatment depends entirely on which of several quite different causes is behind it. Trying to suppress the noise without identifying the cause rarely works and often makes it worse.

Work out which kind it is

Alert barking. Triggered by something seen or heard: someone at the door, a passer-by, another dog. Short bursts, often at a window or gate, stopping when the trigger leaves.

Attention barking. Aimed at you. The dog looks directly at you, pauses to check whether it worked, and barks again. It continues because at some point it worked.

Boredom barking. Long, repetitive, often monotone, when the dog is alone or has nothing to do. Common in working breeds in small homes.

Anxiety barking. Starts shortly after you leave and continues. Usually with pacing, drooling, destruction near doors, or house soiling. This is separation anxiety and it needs proper treatment, not a correction.

Frustration barking. At a fence, a lead or a barrier, when the dog wants to reach something and cannot.

What helps, by cause

Alert barking. Block the view: film on the window, move the sofa away from it, close the curtains. Thank the dog, then call it away and reward it for coming. You are not stopping it noticing; you are shortening its response.

Attention barking. Ignore the barking entirely and reward quiet. Expect it to get worse for several days before it improves; a behaviour that used to work gets tried harder before it is dropped. Intermittent responses teach it more strongly than consistent ones.

Boredom. More physical exercise, and more importantly more mental work: scent games, food puzzles, training sessions, chews. Twenty minutes of nose work tires a dog more than an hour of walking.

Anxiety. Do not punish it, which makes it worse. This needs a structured plan: gradual desensitisation to departure cues, building up alone time in very small steps, and in some cases medication alongside the behaviour work.

Frustration. Manage the environment, and train an alternative behaviour to do instead.

What does not work

Shouting, which the dog reads as joining in. Punishment after the fact, which the dog cannot connect to the barking. Anti-bark collars, which suppress the sound while leaving the underlying anxiety or frustration untouched, and which can create fear and redirected aggression.

Rule out pain first

A dog whose barking has changed recently, particularly an older dog barking at night or into empty rooms, should be examined. Pain, deafness, failing sight and canine cognitive dysfunction all produce vocalising, and none of them respond to training.

When to come in

Barking that has recently started or changed. Barking in an older dog, especially at night. Barking with pacing, drooling or destruction when left alone. Or barking you have not been able to change with the measures above.